JP2666503B2 - Magnetic powder fluid - Google Patents

Magnetic powder fluid

Info

Publication number
JP2666503B2
JP2666503B2 JP2013674A JP1367490A JP2666503B2 JP 2666503 B2 JP2666503 B2 JP 2666503B2 JP 2013674 A JP2013674 A JP 2013674A JP 1367490 A JP1367490 A JP 1367490A JP 2666503 B2 JP2666503 B2 JP 2666503B2
Authority
JP
Japan
Prior art keywords
magnetic powder
magnetic
resin
coated
specific gravity
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2013674A
Other languages
Japanese (ja)
Other versions
JPH03219602A (en
Inventor
宜弘 山村
正宏 小川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
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Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP2013674A priority Critical patent/JP2666503B2/en
Publication of JPH03219602A publication Critical patent/JPH03219602A/en
Application granted granted Critical
Publication of JP2666503B2 publication Critical patent/JP2666503B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/44—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of magnetic liquids, e.g. ferrofluids
    • H01F1/447—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of magnetic liquids, e.g. ferrofluids characterised by magnetoviscosity, e.g. magnetorheological, magnetothixotropic, magnetodilatant liquids

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Colloid Chemistry (AREA)
  • Soft Magnetic Materials (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、樹脂膜コーティングした軟質磁性体粉また
は磁性体膜コーティングした樹脂粉のコーティング磁性
粉を液体中に分散（浮遊懸濁）させた磁粉流体に関する
ものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] In the present invention, a soft magnetic powder coated with a resin film or a coated magnetic powder of a resin powder coated with a magnetic film is dispersed (suspended) in a liquid. It relates to magnetic powder fluid.

〔従来の技術〕[Conventional technology]

本発明に係る磁粉流体は、近年開発・実用化が進んで
いる磁粉流体に近いものと考えられる。The magnetic powder fluid according to the present invention is considered to be close to a magnetic powder fluid that has been developed and put into practical use in recent years.

磁粉流体とは、直径10nm程度の微細な磁性粒子（Fe3O
4超微粒子）をオレイン酸ナトリウムなどの界面活性剤
で表面を覆って液中に浮遊させた懸濁液であり、通常の
遠心力や磁場によって磁性粒子の凝集や沈降を生ぜず、
あたかも液体自身が磁性をもつかのような挙動を示す。
即ち、磁性粒子と液とが分離したり、磁性粒子のみが磁
界によって吸着されるということはない。磁性流体を実
用化したものとして、磁気シール（宇宙服、真空装置の
軸受）やスピーカーのダンピング材料などがある。Magnetic powder fluid refers to fine magnetic particles (Fe 3 O
4 ultra-fine particles) is a suspension in which the surface is suspended in a liquid by covering the surface with a surfactant such as sodium oleate, and does not cause aggregation or sedimentation of magnetic particles due to normal centrifugal force or magnetic field.
It behaves as if the liquid itself has magnetism.
That is, the magnetic particles and the liquid are not separated, and only the magnetic particles are not adsorbed by the magnetic field. Practical use of magnetic fluids includes magnetic seals (space suits, bearings for vacuum devices) and damping materials for speakers.

他方、この磁性流体をエンジンマウント、TEMS（トヨ
タエレクトロニックモデュレイティド・サスペンショ
ン）などの減衰力・バネ定数の変化に用いる試みがなさ
れているが、Fe3O4超微粒子が液中に安定に分散されか
つ粒子径があまりにも小さいために、オリフィス部の粘
度変化が大きなものとならず、温度変化による粘度変化
と同程度にすぎない。On the other hand, attempts have been made to use this magnetic fluid for changes in damping force and spring constant of engine mounts, TEMS (Toyota Electronic Modulated Suspension), etc., but Fe 3 O 4 ultra-fine particles stably remain in the liquid. Since the particles are dispersed and the particle diameter is too small, the change in viscosity at the orifice portion does not become large, and is only about the same as the change in viscosity due to the temperature change.

〔発明が解決しようとする課題〕[Problems to be solved by the invention]

磁性流体中の磁性粒子は磁界によって液中で配向する
のみで、磁性粒子が凝集することにはならないので、十
分な磁界による粘度変化制御はできない。The magnetic particles in the magnetic fluid are only orientated in the liquid by the magnetic field, and the magnetic particles do not agglomerate, so that the viscosity change cannot be sufficiently controlled by the magnetic field.

本発明の目的は、通常は磁性粒子（粉体）が液中に分
散している液体（流体）であって、磁界によって磁性粒
子が凝集して粘度の高くなる部分の生じる流体を提供す
ることである。SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid (fluid) in which magnetic particles (powder) are usually dispersed in a liquid, in which a magnetic particle aggregates due to a magnetic field and a portion having a high viscosity is generated. It is.

一方、エンジンマウントなどの減衰力を制御するため
に、ステッピングモーターなどでオリフィスの径を変化
させる方法は、応答性が悪く、アクティブコントローラ
としては不十分であり、磁性流体の採用もうまくいって
いない。On the other hand, a method of changing the diameter of an orifice by a stepping motor or the like to control the damping force of an engine mount or the like has poor response, is insufficient as an active controller, and has not been successful in using a magnetic fluid.

本発明の別の目的は、エンジンマウントなどの減衰力
を制御するのに利用出来る磁性粒子が液中に分散してい
る液体（流体）を提供することである。Another object of the present invention is to provide a liquid (fluid) in which magnetic particles that can be used to control damping force of an engine mount or the like are dispersed in the liquid.

〔課題を解決するための手段〕[Means for solving the problem]

上述の目的が、粒子径0.1〜100μｍの軟質磁性体粉の
それぞれを樹脂コーティング膜で覆ってコーティング磁
性粉とし、該コーティング磁性粉の比重を分散させる液
体溶媒の比重の90〜110％に前記樹脂コーティング膜の
被覆量で調整し、かつ該コーティング磁性粉を前記液体
溶媒中にその５〜50体積％分散させている第１態様の磁
粉流体によって達成される。The above object is achieved by coating each of the soft magnetic powder having a particle diameter of 0.1 to 100 μm with a resin coating film to form a coated magnetic powder, and dispersing the specific gravity of the coated magnetic powder to 90 to 110% of the specific gravity of a liquid solvent. This is achieved by the magnetic powder fluid according to the first aspect, wherein the magnetic powder is adjusted by the coating amount of the coating film and the coated magnetic powder is dispersed in the liquid solvent in an amount of 5 to 50% by volume.

また、粒子径0.1〜100μｍの樹脂粉のそれぞれを磁性
体コーティング膜で覆ってコーティング磁性粉とし、該
コーティング磁性粉の比重を分散させる液体溶媒の比重
の90〜110％に前記磁性体コーティング膜の被覆量で調
整し、かつ該コーティング磁性粉を前記液体溶媒中にそ
の５〜50体積％分散させている第２態様の磁粉流体によ
っても上述の目的が達成される。Further, each of the resin powders having a particle diameter of 0.1 to 100 μm is covered with a magnetic substance coating film to form a coating magnetic powder, and the specific gravity of the coating magnetic powder is dispersed to 90 to 110% of the specific gravity of the liquid solvent. The above-mentioned object is also achieved by the magnetic powder fluid of the second embodiment in which the coating amount is adjusted and the coating magnetic powder is dispersed in the liquid solvent by 5 to 50% by volume.

〔作用〕[Action]

本発明に係る第１態様の磁粉流体は、第１図に示すよ
うに、個々の軟質磁性体粉１の全面が樹脂コーティング
膜２で覆われている樹脂膜コーティング磁性粉３を液体
溶媒４中に分散（浮遊懸濁）させたものである。As shown in FIG. 1, a magnetic powder fluid according to a first embodiment of the present invention is obtained by mixing a resin film-coated magnetic powder 3 in which the entire surface of each soft magnetic powder 1 is covered with a resin coating film 2 in a liquid solvent 4. (Suspension).

軟質磁性体粉は、粒子径が0.1〜100μｍ、好ましく
は、１〜30μｍであるFe,Co,Ni,パーマロイなどの軟質
磁性材料である。粒子径0.1μｍ以下では、凝集力が弱
くなり（すなわち、粘度変化量が小さくなる）となり、
好ましくなく、一方、100μｍ以上では、液中での分散
性が悪くなり、使用上も反応性が悪くなる。なお、軟質
磁性材料の形状は、樹脂コーティング後の比重が小さく
なるように海綿状ないし樹枝状又は燐片状が適してお
り、これは樹脂コーティング時に気泡が多くなり比重が
小さく成るからである。もちろん、一般的な球状でもよ
い。The soft magnetic material powder is a soft magnetic material such as Fe, Co, Ni, and Permalloy having a particle size of 0.1 to 100 μm, preferably 1 to 30 μm. When the particle diameter is 0.1 μm or less, the cohesive strength becomes weak (that is, the amount of change in viscosity becomes small),
On the other hand, if it is 100 μm or more, the dispersibility in the liquid is poor, and the reactivity in use is poor. The shape of the soft magnetic material is suitably spongy, dendritic, or scaly so that the specific gravity after resin coating is small, because the number of air bubbles increases during resin coating and the specific gravity becomes small. Of course, a general spherical shape may be used.

コーティングする樹脂は、その比重が小さいほうが適
しており、ほとんどの樹脂が使用可能であり、例えば、
ポリプロピレン、ポリメチルメタクリレート（PMMA）、
ナイロン、ポリスチレンなどがある。樹脂コーティング
量は、得られる樹脂膜コーティング磁性粉の比重を液体
溶媒比重の90〜110％（好ましくは、同じ＝100％）にす
る量であって、樹脂膜コーティング磁性粉と液体の比重
をほぼ同じにすれば、該磁性粉は液中に浮遊し、分散さ
れる。樹脂膜コーティング磁性粉の比重が液体溶媒比重
の±10％を越えると、分散状態から分離状態に移行して
しまう。As for the resin to be coated, the smaller the specific gravity, the more suitable, most resins can be used, for example,
Polypropylene, polymethyl methacrylate (PMMA),
There are nylon and polystyrene. The resin coating amount is an amount that makes the specific gravity of the obtained resin film-coated magnetic powder 90 to 110% (preferably the same = 100%) of the specific gravity of the liquid solvent. In the same case, the magnetic powder floats in the liquid and is dispersed. When the specific gravity of the resin-coated magnetic powder exceeds ± 10% of the specific gravity of the liquid solvent, the magnetic powder shifts from the dispersed state to the separated state.

軟質磁性体粉１に樹脂コーティング膜２を被覆カプセ
ル化する方法は、いくつかあるが代表的な方法を第２図
に示す。この場合、樹脂の超微粒子５（粒径が軟質磁性
粉１の1/10程度）を用意し、帯電し、軟質磁性粉１と混
合することによって、粉体表面に付着する。この粒子を
空中で加熱して樹脂の超微粒子５が融着し、コーティン
グ膜２となる。この工程を数回繰り返して粒子全体の比
重を混合する液体溶媒の比重とほぼ等しくなるようにす
る。There are several methods for encapsulating the soft magnetic powder 1 with the resin coating film 2, and a typical method is shown in FIG. In this case, resin ultrafine particles 5 (having a particle size of about 1/10 that of the soft magnetic powder 1) are prepared, charged, mixed with the soft magnetic powder 1, and adhere to the powder surface. The particles are heated in the air to fuse the resin ultrafine particles 5 to form the coating film 2. This step is repeated several times so that the specific gravity of the whole particles becomes substantially equal to the specific gravity of the liquid solvent to be mixed.

軟質磁性体粉１自身の比重が大きいにもかかわらず、
樹脂コーティング膜２の厚さを厚くしないで（薄くし
て）樹脂コーティング磁性粉とする場合には、その液体
溶媒４は比重が出来るだけ大きい液が適しており、例え
ば、フッ素系オイル は、粘度20〜50c.s.（センチストーク）で比重が1.90〜
1.93であり、また は、粘度53c.s.で比重が1.86である。Despite the large specific gravity of the soft magnetic powder 1 itself,
When the resin coating film 2 is not thickened (thinned) to be resin-coated magnetic powder, the liquid solvent 4 is preferably a liquid having a specific gravity as large as possible. Has a viscosity of 20-50 c.s. (centistoke) and a specific gravity of 1.90-
1.93, and Has a viscosity of 53 c.s. and a specific gravity of 1.86.

本発明に係る第２態様の磁粉流体は、第３図に示すよ
うに、個々の樹脂粉６の全面が磁性体コーティング膜７
で覆われている磁性体膜コーティング磁性粉８を液体溶
媒４中に分散（浮遊懸濁）させたものである。As shown in FIG. 3, the magnetic powder fluid of the second embodiment according to the present invention is such that the entire surface of each resin powder 6 is coated with a magnetic material coating film 7.
The magnetic powder coated with the magnetic material film 8 is dispersed (suspended and suspended) in the liquid solvent 4.

樹脂粉６は、粒子径が0.1〜100μｍ、好ましくは、１
〜30μｍである上述したコーティング樹脂の材料から作
られる。粒子径0.1μｍ以下では、凝集力が弱くなり
（即ち、粘度変化量が小さくなり）、好ましくなく、一
方、100μｍ以上では、液中での分散性が悪くなり、使
用上も反応性が悪くなる。なお、樹脂粉の形状は、一般
的に球状であり、特に、コーティング磁性体膜７の厚さ
を厚くするために、中空体としても良い。The resin powder 6 has a particle diameter of 0.1 to 100 μm, preferably 1 to 100 μm.
It is made from the above-mentioned coating resin material having a size of 3030 μm. When the particle diameter is 0.1 μm or less, the cohesive strength is weakened (that is, the amount of change in viscosity becomes small), which is not preferable. On the other hand, when the particle diameter is 100 μm or more, the dispersibility in a liquid is deteriorated, and the reactivity in use is deteriorated. . Note that the shape of the resin powder is generally spherical, and in particular, it may be a hollow body in order to increase the thickness of the coating magnetic film 7.

コーティイグする磁性体は、Ni,Co,Feなどの軟質磁性
材料であり、そのコーティング量は、上述したように得
られる磁性体膜コーティング磁性粉８の比重を液体溶媒
比重の90〜110％（好ましくは、同じ＝100％）にする量
であって、比重をほぼ同じにすれば、該磁性粉は液中に
浮遊し、分散される。磁性体膜コーティング磁性粉の比
重が液体溶媒比重の±10％を越えると、分散状態から分
離状態に移行してしまう。The magnetic material to be coated is a soft magnetic material such as Ni, Co, Fe, etc., and its coating amount is set so that the specific gravity of the magnetic film coating magnetic powder 8 obtained as described above is 90 to 110% of the specific gravity of the liquid solvent (preferably). Are the same = 100%), and if the specific gravities are almost the same, the magnetic powder is suspended and dispersed in the liquid. If the specific gravity of the magnetic powder coated with the magnetic film exceeds ± 10% of the specific gravity of the liquid solvent, the magnetic powder shifts from the dispersed state to the separated state.

樹脂粉６に磁性体コーティング膜７を被覆カプ公知の
無電解メッキ法が好ましい。Fe膜を被覆するには、無電
解メッキ法でNi,Coを極薄く形成した後で、Feを電解メ
ッキすればよい。したがって、PMMAなどの樹脂の粉体６
をソープフリー乳化重合法で作り、この樹脂粉６に活性
化処理の前処理を施し、水洗し、Ni−Ｐ（94〜95:6〜
５）またはCo−Ｐ（98〜99:2〜１）の無電解メッキ浴中
に浸漬・撹拌してメッキする。メッキ膜（磁性体コーテ
ィング膜）厚さを主に浸漬時間（他にメッキ液を濃度、
浴温度など）によってコントロールして、磁性体膜コー
ティング磁性粉の比重を混合する液体溶媒の比重とほぼ
同じとなるようにする。次に、メッキ後に水洗し、乾燥
して、磁性粉８を得る。このようにして得た磁性体膜コ
ーティング磁性粉８を所定の比重の液体溶媒４中に添加
し、撹拌して本発明に係る磁粉流体となる。A known electroless plating method is preferred in which the resin powder 6 is coated with the magnetic material coating film 7. In order to cover the Fe film, Ni and Co may be formed extremely thin by an electroless plating method, and then Fe may be electroplated. Therefore, resin powder 6 such as PMMA
Is prepared by a soap-free emulsion polymerization method, and the resin powder 6 is subjected to a pretreatment for an activation treatment, washed with water, and Ni-P (94 to 95: 6 to
5) Dip and stir in an electroless plating bath of Co-P (98-99: 2-1) to perform plating. The plating film (magnetic material coating film) thickness mainly depends on the immersion time (other than the concentration of plating solution,
(Eg, bath temperature) so that the specific gravity of the magnetic film-coated magnetic powder is substantially the same as the specific gravity of the liquid solvent to be mixed. Next, after plating, it is washed with water and dried to obtain a magnetic powder 8. The magnetic film-coated magnetic powder 8 thus obtained is added to the liquid solvent 4 having a predetermined specific gravity and stirred to obtain the magnetic powder fluid according to the present invention.

本発明に係る第１および第２の態様の磁粉流体でのコ
ーティング磁性粉の液体溶媒中の量が体積％より少ない
と、十分な粘度変化量が得られなくなりかつ応答性が悪
くなり、一方50体積％よりも多いと、初期粘度が著しく
上昇又は液状を保たないようになって、何れも好ましく
ない。When the amount of the magnetic powder coated with the magnetic powder fluid of the first and second aspects of the present invention in the liquid solvent is less than volume%, a sufficient amount of change in viscosity cannot be obtained and responsiveness deteriorates. When the content is more than the volume%, the initial viscosity is remarkably increased or the liquid is not maintained, and both are not preferable.

本発明に係る磁粉流体と従来の磁性流体とは、第４図
に示すように、磁界による磁性粒子と液体溶媒の分離量
が異なる。磁性流体は直径10〜20mm程度のFe3O4の表面
に、第５図に示すように、オレイン酸ナトリウムなどの
界面活性剤を吸着させ、液体溶媒中に安定に分散させた
ものである。磁性粒子は単磁区（一般に磁区の大きさは
100mm程度）であり、界面活性剤の親油基（疎水基）の
ために、液中に安定して存在しており、50mm程度まで磁
界をかけても磁性粒子と液（分散媒）が分離することは
ない。即ち、磁性粒子が分散媒と分離しないのは、磁
性粒子が微細で磁界をかけても粒子１個当たりの力はあ
まり大きいものとはならず、力が分散されるために、液
全体で力を受けるようになること、及び界面活性剤の
末端は液体であり、分散媒も液体であり、非常に相溶性
に富んでいる（相互作用が大きい）ことが大きな理由で
ある。一方、本発明に係る磁粉流体では、磁性粒子（ま
たは樹脂粒子）径を0.1〜100μｍとして、樹脂（または
磁性体）コーティングで比重を液体媒体比重とほぼ同じ
にして粒子の沈降を防ぎ、分散媒中に均一に分散させた
ものであるので、粒子は磁性流体の場合よりも大きく、
粒子１個当たりの磁界による力は大きなり、さらに、粒
子表面が樹脂の固体であって液（分散媒）との相互作用
は小さい。従って、磁界を印加することにより容易に樹
脂膜（磁性体膜）コーティング磁性粉（粒子）を液（分
散媒）と分離させることが出来る。As shown in FIG. 4, the magnetic powder fluid according to the present invention and the conventional magnetic fluid differ in the amount of magnetic particles and liquid solvent separated by a magnetic field. As shown in FIG. 5, the magnetic fluid has a surfactant such as sodium oleate adsorbed on the surface of Fe 3 O 4 having a diameter of about 10 to 20 mm and is stably dispersed in a liquid solvent. A magnetic particle is a single magnetic domain (generally the size of the magnetic domain is
(Approx. 100 mm) and is stable in the liquid due to the lipophilic group (hydrophobic group) of the surfactant. Even when a magnetic field is applied up to about 50 mm, the magnetic particles and the liquid (dispersion medium) separate. I will not do it. That is, the magnetic particles do not separate from the dispersion medium because the magnetic particles are fine and the force per particle is not so large even when a magnetic field is applied, and the force is dispersed. The reason is that the surfactant is liquid and the terminal of the surfactant is liquid, and the dispersion medium is also liquid and very compatible (large interaction). On the other hand, in the magnetic powder fluid according to the present invention, the magnetic particles (or resin particles) have a diameter of 0.1 to 100 μm, and the specific gravity of the resin (or magnetic material) coating is substantially equal to the specific gravity of the liquid medium to prevent sedimentation of the particles. Because they are evenly dispersed inside, the particles are larger than in magnetic fluids,
The force by the magnetic field per particle is large, and the particle surface is a resin solid, and the interaction with the liquid (dispersion medium) is small. Therefore, the magnetic powder (particles) coated with the resin film (magnetic film) can be easily separated from the liquid (dispersion medium) by applying a magnetic field.

さらに、本発明に係る第２態様の磁粉流体では、個々
のコーティング磁性粉８の表面はNi,Coなどの磁性体金
属であるから磁石に直接にないし連鎖的に吸着され、場
合によっては、第６図に示すように、磁石のＮ極41とＳ
極42とを結ぶ磁力線方向に沿って磁性粉が連続的に接触
して並び磁力線は連続したものとなる。一方、第１態様
の磁粉流体では、第７図に示すように、Ｎ極41とＳ極42
とを結ぶ磁力線方向に沿ってコーティング磁性粉３を直
列に並んでいるが、相互に接触しているのは樹脂膜２で
あるので、連続した磁力線とはならず、樹脂の非磁性膜
を通るために磁気抵抗が大きくなってしまう。したがっ
て、第２態様の磁粉流体のほうが、磁極間に大きな磁界
が得られ、磁性粉の吸着力も強い。Furthermore, in the magnetic powder fluid of the second embodiment according to the present invention, the surface of each coated magnetic powder 8 is a magnetic metal such as Ni or Co, and is directly or chain-adsorbed to the magnet. As shown in FIG. 6, the N pole 41 of the magnet and the S pole
The magnetic powder is continuously contacted along the direction of the line of magnetic force connecting the pole 42, and the lines of magnetic force are continuous. On the other hand, in the magnetic powder fluid of the first embodiment, as shown in FIG.
The coating magnetic powders 3 are arranged in series along the direction of the lines of magnetic force connecting the two, but since the resin films 2 are in contact with each other, they do not form continuous lines of magnetic force but pass through a non-magnetic film of resin. Therefore, the magnetic resistance increases. Accordingly, the magnetic powder fluid of the second embodiment provides a larger magnetic field between the magnetic poles, and has a stronger magnetic powder adsorption force.

〔実施例〕〔Example〕

以下、添付図面を参照して、本発明の実施態様例によ
って本発明を詳しく説明する。Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

先ず、樹脂膜コーティング磁性粉のために軟質磁性体
粉およびコーティング用樹脂そして溶媒液体として、例
えば、次のものを用意する。First, the following are prepared as the soft magnetic powder, the coating resin, and the solvent liquid for the resin film-coated magnetic powder.

軟質磁性体粉：純Fe、球状、直径2.5μｍ、比重7.87 コーティング用樹脂:PMMA 液体溶媒：フッ素系オイル、比重1.90 この場合に、コーティング後の樹脂膜コーティング磁
性粉の比重を液体溶媒比重と同じにするには、樹脂膜コ
ーティング磁性粉の直径を5.2μｍにする。なお、これ
は球状磁性粉（その内部に気泡はない磁性粒子）の場合
であって、磁性粉が海綿状ないし樹脂状又は鱗片状のと
きには、球状の場合よりも薄い樹脂コーティング膜でよ
い。フッ素系オイルの液体溶媒の中に樹脂膜コーティン
グ磁性粉を25Vol.％添加し、混合して均一分散の第１態
様の磁粉流体を調製する。Soft magnetic powder: pure Fe, spherical, diameter 2.5 μm, specific gravity 7.87 Coating resin: PMMA Liquid solvent: fluorine-based oil, specific gravity 1.90 In this case, in order to make the specific gravity of the resin film-coated magnetic powder after coating equal to the specific gravity of the liquid solvent, the diameter of the resin film-coated magnetic powder is set to 5.2 μm. Note that this is the case of spherical magnetic powder (magnetic particles having no air bubbles therein), and when the magnetic powder is spongy, resinous, or scaly, a thinner resin coating film than in the case of a spherical shape may be used. To a liquid solvent of a fluorinated oil, 25 vol.% Of a magnetic powder coated with a resin film is added and mixed to prepare a uniformly dispersed magnetic powder fluid of the first embodiment.

また、磁性体膜コーティング磁性粉としての樹脂粉お
よびコーティング（メッキ）用磁性膜そして溶媒液体
に、例えば、次のものを用意する。For example, the following are prepared for the resin powder as the magnetic powder for coating the magnetic film, the magnetic film for coating (plating), and the solvent liquid.

樹脂粉:PMMA、球状、直径２μｍ、比重1.15 コーティング膜:Ni無電解メッキ膜、比重8.91 コーティング後の直径:2.07μｍ 液体溶媒：同じフッ素系オイル この場合に、磁性体膜コーティング磁性粉の比重を液
体溶媒比重と同じにするために、該磁性粉の直径を2.07
μｍとしてあり、メッキ厚さは0.035μｍと樹脂膜より
もかなり薄くてよい。フッ素系オイルの液体溶媒の中に
磁性体膜コーティング磁性粉を25Vol.％添加し、混合し
て均一分散の第２態様の磁粉流体を調製する。Resin powder: PMMA, spherical, diameter 2 μm, specific gravity 1.15 Coating film: Ni electroless plating film, specific gravity 8.91 Diameter after coating: 2.07 μm Liquid solvent: same fluorine-based oil In this case, the specific gravity of the magnetic powder coated magnetic powder The diameter of the magnetic powder should be 2.07 to make it the same as the specific gravity of the liquid solvent.
μm, and the plating thickness is 0.035 μm, which may be considerably smaller than the resin film. A magnetic powder coated with a magnetic material film is added in a volume of 25 Vol.% To a liquid solvent of a fluorinated oil and mixed to prepare a magnetic powder fluid of the second embodiment which is uniformly dispersed.

このように用意した第１態様の磁粉流体を第８〜10図
（断面図）に示すエンジンマウントの封入液体（流体）
に適用し、その作動を説明する。The magnetic powder fluid of the first embodiment prepared in this manner is filled with liquid (fluid) in an engine mount shown in FIGS. 8 to 10 (cross-sectional views).
And its operation will be described.

第８〜10図のエンジンマウントにおいて、エンジン側
固定ボルト11及び第１の枠体としてのスタビライザ12が
エンジン側に固定され、弾性体13がスタビライザ12に接
続されている。ボデー14には第２の枠体としてのエンジ
ンマウント容器15が固定される。弾性体13はこれら２つ
の枠体12、15を連結し、かつその一部がエンジンマウン
ト容器15とで構成する室16の壁面となっている。室16の
下方には室17が形成され、該室17は大気と連通してお
り、弾性隔膜18で室16と隔てられている。この室16に本
発明に係る磁粉流体19が封入されている。室16の中にオ
リフィス（開口）21を有するオリフィス板22が設けら
れ、このオリフィス21を囲むコイル23がオリフィス板22
に取りつけられている。さらに、このコイル23に電流を
供給する電力供給手段のシステムが、予め走行条件に応
じて電流量を変化させることを記憶させたコンピュータ
24と、これに情報を与えるセンサ25と、コンピュータ24
により電流量を変化させて出力する可変抵抗器26と、こ
の可変抵抗器26とコイル23とを繋ぐ電線27とからなる。8 to 10, an engine-side fixing bolt 11 and a stabilizer 12 as a first frame are fixed to the engine side, and an elastic body 13 is connected to the stabilizer 12. An engine mount container 15 as a second frame is fixed to the body 14. The elastic body 13 connects the two frame bodies 12 and 15, and a part of the elastic body 13 forms a wall surface of a chamber 16 formed by the engine mount container 15. A chamber 17 is formed below the chamber 16 and communicates with the atmosphere. The chamber 17 is separated from the chamber 16 by an elastic diaphragm 18. In this chamber 16, the magnetic powder fluid 19 according to the present invention is sealed. An orifice plate 22 having an orifice (opening) 21 is provided in the chamber 16, and a coil 23 surrounding the orifice 21 is provided with an orifice plate 22.
It is attached to. Further, a computer in which the system of the power supply means for supplying current to the coil 23 stores in advance that the amount of current is changed in accordance with running conditions.
24, a sensor 25 for providing information thereto, and a computer 24
The variable resistor 26 changes the amount of current and outputs the same, and an electric wire 27 connecting the variable resistor 26 and the coil 23.

エンジンマウントは次のように働く。 The engine mount works as follows.

コイル23に電流を流していない時は、樹脂膜コーティ
ング磁性粉は液体溶媒中を均一分散（浮遊）しており、
第８図に示すように、オリフィス21内にも均一な磁粉流
体19が存在して、オリフィスの抵抗は小さく、エンジン
マウントのばね定数も小さい。When no current is applied to the coil 23, the resin-coated magnetic powder is uniformly dispersed (floating) in the liquid solvent,
As shown in FIG. 8, the uniform magnetic powder fluid 19 is also present in the orifice 21, the resistance of the orifice is small, and the spring constant of the engine mount is also small.

走行条件に応じてセンサ25よりコンピュータ24へ信号
が送られ、可変抵抗器26より電流が流れると、コイル23
によって磁界が発生し、磁粉流体19中の樹脂膜コーティ
ング磁性粉がオリフィス21（即ち、コイル23）内に移動
し凝集して磁性粉吸着層28を形成する。電流量が比較的
小さいと、第９図に示すように、樹脂膜コーティング磁
性粉28はオリフィス21を塞がない程度にコイル23の壁面
に吸着される。さらに電流量を増加させると、第10図に
示すように、吸着された樹脂膜コーティング磁性粉28が
オリフィス21を完全に塞ぐ。このように電流量によって
オリフィス21の通路断面積を変化させて、エンジンマウ
ントのばね定数を可変として、大きくすることが出来
る。When a signal is sent from the sensor 25 to the computer 24 according to the running conditions and a current flows from the variable resistor 26, the coil 23
As a result, a magnetic field is generated, and the resin film-coated magnetic powder in the magnetic powder fluid 19 moves into the orifice 21 (that is, the coil 23) and aggregates to form the magnetic powder adsorption layer 28. If the amount of current is relatively small, as shown in FIG. 9, the resin film-coated magnetic powder 28 is adsorbed on the wall surface of the coil 23 to such an extent that the orifice 21 is not blocked. When the current is further increased, the adsorbed resin film-coated magnetic powder 28 completely blocks the orifice 21 as shown in FIG. As described above, by changing the passage cross-sectional area of the orifice 21 depending on the amount of current, the spring constant of the engine mount can be changed and increased.

オリフィス断面積（当初開口面積、12mm2のもの）が
コイル23の磁界強度によって変化する様子を第11図に示
す。磁界強度が300エルステッド（Oe）を越えると、樹
脂膜コーティング磁性粉28がオリフィス21の周囲に吸着
され始め、磁性粉吸着層28が徐々に厚くなりオリフィス
の断面積が小さくなる。1250エルステッド程度でほぼ完
全に塞がれ、1500エルステッドの時には10kg/cm2以上の
圧力に耐えることが可能である。FIG. 11 shows how the orifice cross-sectional area (the initial opening area is 12 mm 2 ) changes according to the magnetic field strength of the coil 23. When the magnetic field intensity exceeds 300 Oe (Oe), the resin-coated magnetic powder 28 starts to be adsorbed around the orifice 21, the magnetic powder adsorption layer 28 gradually thickens, and the cross-sectional area of the orifice decreases. It is almost completely closed at about 1250 Oersted and can withstand a pressure of 10 kg / cm 2 or more at 1500 Oersted.

エンジンマウントのばね定数制御（オリフィス断面積
制御）が第12図に示すコンピュータ24の作動フローチャ
ートに従って自動車の運転・走行条件に応じて行われ
る。この場合には、ばね定数を３段階に変えることが出
来て、スタート作動中、悪路、急加速、急減速、急旋回
の時にコイル23への電流値を高めることでばね定数を高
めている。即ち、スタート時及び悪路では電流値が4Aと
大きく、オリフィス断面積がゼロとなり、また、加速度
が3.0m/s2以上でも電流値が4Aになる。加速度が2.0〜3.
0m/s2の間では電流値が2Aになって、オリフィス断面積
が半分の6mm2に減少する。走行中の加速度が2.0m/s2以
下では、電流値がゼロになって、オリフィス断面積は当
初のままである。ばね定数を段階的に変えるのではな
く、連続的に変えることも可能である。The control of the spring constant of the engine mount (control of the cross-sectional area of the orifice) is performed according to the driving / running conditions of the vehicle according to the operation flowchart of the computer 24 shown in FIG. In this case, the spring constant can be changed in three stages, and the spring constant is increased by increasing the current value to the coil 23 during a start operation, on a rough road, sudden acceleration, sudden deceleration, and sudden turning. . That is, at the start and on a rough road, the current value is as large as 4 A, the orifice cross-sectional area becomes zero, and the current value becomes 4 A even when the acceleration is 3.0 m / s 2 or more. The acceleration is 2.0-3.
During 0 m / s 2 , the current value becomes 2 A, and the cross-sectional area of the orifice is reduced by half to 6 mm 2 . When the acceleration during traveling is 2.0 m / s 2 or less, the current value becomes zero, and the orifice cross-sectional area remains as it was. Instead of changing the spring constant stepwise, it is also possible to change the spring constant continuously.

第13図は第８図に示したエンジンマウントの一部構造
を変更したもので、オリフィス21に少ない電流量で大き
な磁界を形成するようにコイル31を有するヨーク32を設
けてある。このようなコイル付ヨーク32及びオリフィス
板22の平面図が第14図である。このエンジンマウントの
構成及び動作は第８〜12図に関連して説明したこととほ
ぼ同じである。FIG. 13 is a partial modification of the engine mount shown in FIG. 8, in which a yoke 32 having a coil 31 is provided in the orifice 21 so as to form a large magnetic field with a small amount of current. FIG. 14 is a plan view of such a coiled yoke 32 and the orifice plate 22. FIG. The structure and operation of this engine mount are substantially the same as those described with reference to FIGS.

上述での第１態様の磁粉流体に代えて磁性体膜コーテ
ィング磁性粉を用いた第２態様の磁粉流体を同じエンジ
ンマウントの封入液体に使用することができる。この場
合には、第６図と関連して説明したように磁性粉の吸着
力（凝集力）が樹脂膜コーティング磁性粉よりも大き
く、第15図に示すように、オリフィス長さ2cmでオリフ
ィス部に発生する差圧は直線Ａのように磁界の強さに比
例して生じ、直線Ｂでの樹脂膜コーティング磁性粉の場
合よりも大きい。The magnetic powder fluid of the second embodiment using a magnetic film-coated magnetic powder instead of the magnetic powder fluid of the first embodiment described above can be used as the liquid to be sealed in the same engine mount. In this case, the adsorbing force (cohesion) of the magnetic powder is greater than that of the magnetic powder coated with the resin film as described in connection with FIG. 6, and as shown in FIG. Is generated in proportion to the strength of the magnetic field, as indicated by the straight line A, and is larger than that of the resin film-coated magnetic powder on the straight line B.

〔発明の効果〕〔The invention's effect〕

上述したように、本発明によれば、通常の磁界のかか
っていない時には均一分散状態であり、磁界強度に応じ
て凝集する磁性粒子（樹脂膜または磁性体膜コーティン
グ磁性粉）を含有する磁粉流体が得られる。樹脂で磁性
粒子の金属をコーティングしていると、逆構造の磁性体
膜コーティング磁性粉よりも凝集力は弱いが、防錆効果
が得られて、磁性流体の場合よりも耐久性が向上する。
また、エンジンマウントに磁粉流体を適用することは、
ステッピングモータ方式に比べて可動部がないだけ信頼
性が向上する。As described above, according to the present invention, a magnetic powder fluid containing magnetic particles (resin film or magnetic film-coated magnetic powder) that is in a uniformly dispersed state when a normal magnetic field is not applied and that aggregates according to the magnetic field intensity Is obtained. When the metal of the magnetic particles is coated with the resin, the cohesive force is weaker than that of the magnetic powder coated with the magnetic film having the reverse structure, but the rust prevention effect is obtained and the durability is improved as compared with the case of the magnetic fluid.
Also, applying magnetic powder fluid to the engine mount
As compared with the stepping motor system, the reliability is improved because there are no moving parts.

【図面の簡単な説明】[Brief description of the drawings]

第１図は、本発明に係る第１態様の磁粉流体の概略図で
あり、 第２図は、軟質磁性体粉に樹脂のコーティング膜を形成
する工程図であり、 第３図は、本発明に係る第２態様の磁粉流体の概略図で
あり、 第４図は、磁性粒子直径と、磁界による粒子と液との分
離量との関係を示すグラフであり、 第５図は、磁性流体の磁性粒子及び界面活性剤の概略図
であり、 第６図は、Ｎ極とＳ極との間の磁性体膜コーティング磁
性粉の配列を示す概略図であり、 第７図は、Ｎ極とＳ極との間の樹脂膜コーティング磁性
粉の配列を示す概略図であり、 第８図〜第10図は、印加電流値の異なる時のエンジンマ
ウントの概略断面図であり、 第11図は、磁界の強さとエンジンマウントのオリフィス
断面積との関係を示すグラフであり、 第12図は、エンジンマウントのコンピュータ制御のフロ
ーチャート図であり、 第13図は、オリフィス部の構成を変更したエンジンマウ
ントの概略構成図であり、 第14図は、第13図のオリフィス部の平面図であり、 第15図は、オリフィス部での磁界の強さと発生差圧との
関係を示すグラフである。 １……軟質磁性体粉 ２……樹脂コーティング膜 ３……樹脂膜コーティイグ磁性粉 ４……液体溶媒、６……樹脂粉 ７……磁性体コーティング膜 ８……磁性体膜コーティイグ磁性粉 13……弾性体 15……エンジンマウント容器 16……室、19……磁粉流体 21……オリフィス、23……コイル 24……コンピュータ、25……センサ 31……コイル、32……ヨークFIG. 1 is a schematic diagram of a magnetic powder fluid according to a first embodiment of the present invention, FIG. 2 is a process diagram of forming a resin coating film on a soft magnetic powder, and FIG. FIG. 4 is a schematic diagram of a magnetic powder fluid of a second embodiment according to the present invention. FIG. 4 is a graph showing the relationship between the diameter of magnetic particles and the amount of separation between particles and liquid by a magnetic field. FIG. 6 is a schematic view showing magnetic particles and a surfactant, FIG. 6 is a schematic view showing an arrangement of magnetic film coating magnetic powder between an N pole and an S pole, and FIG. FIGS. 8 to 10 are schematic cross-sectional views of an engine mount when applied current values are different, and FIG. 11 is a schematic view showing a magnetic field arrangement. FIG. 12 is a graph showing the relationship between the strength of the engine mount and the cross-sectional area of the orifice of the engine mount. 13 is a schematic diagram of an engine mount in which the configuration of the orifice portion is changed, FIG. 14 is a plan view of the orifice portion in FIG. 13, and FIG. Is a graph showing the relationship between the strength of the magnetic field at the orifice and the generated differential pressure. DESCRIPTION OF SYMBOLS 1 ... Soft magnetic material powder 2 ... Resin coating film 3 ... Resin film coating magnetic powder 4 ... Liquid solvent, 6 ... Resin powder 7 ... Magnetic material coating film 8 ... Magnetic material coating magnetic powder 13 ... ... elastic body 15 ... engine mount container 16 ... chamber, 19 ... magnetic powder fluid 21 ... orifice, 23 ... coil 24 ... computer, 25 ... sensor 31 ... coil, 32 ... yoke

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】粒子径0.1〜100μｍの軟質磁性体粉のそれ
ぞれを樹脂コーティング膜で覆ってコーティング磁性粉
とし、該コーティング磁性粉の比重をを分散させる液体
溶媒の比重の90〜110％に前記樹脂コーティング膜の被
覆量で調整し、かつ該コーティング磁性粉を前記液体溶
媒中にその５〜50体積％分散させている磁粉流体。1. A soft magnetic powder having a particle diameter of 0.1 to 100 μm is coated with a resin coating film to form a coated magnetic powder, and the specific gravity of the coated magnetic powder is reduced to 90 to 110% of the specific gravity of a liquid solvent for dispersing the magnetic powder. A magnetic powder fluid prepared by adjusting the coating amount of a resin coating film and dispersing the coated magnetic powder in the liquid solvent in an amount of 5 to 50% by volume. 【請求項２】粒子径0.1〜100μｍの樹脂粉のそれぞれを
磁性体コーティング膜で覆ってコーティング磁性粉と
し、該コーティング磁性粉の比重を分散させる液体溶媒
の比重の90〜110％に前記磁性体コーティング膜の被覆
量で調整し、かつ該コーティング磁性粉を前記液体溶媒
中にその５〜50体積％分散させている磁粉流体。2. A resin coating having a particle diameter of 0.1 to 100 .mu.m is coated with a magnetic substance coating film to form a coating magnetic powder, and the specific gravity of the liquid solvent is 90 to 110% of the specific gravity of the liquid solvent for dispersing the specific gravity of the coating magnetic powder. A magnetic powder fluid prepared by adjusting the coating amount of a coating film and dispersing the coated magnetic powder in the liquid solvent in an amount of 5 to 50% by volume.
JP2013674A 1990-01-25 1990-01-25 Magnetic powder fluid Expired - Fee Related JP2666503B2 (en)

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JP2013674A JP2666503B2 (en) 1990-01-25 1990-01-25 Magnetic powder fluid

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Application Number Priority Date Filing Date Title
JP2013674A JP2666503B2 (en) 1990-01-25 1990-01-25 Magnetic powder fluid

Publications (2)

Publication Number Publication Date
JPH03219602A JPH03219602A (en) 1991-09-27
JP2666503B2 true JP2666503B2 (en) 1997-10-22

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CN100424370C (en) * 2003-11-26 2008-10-08 赫格纳斯公司 Metallurgical powder composition and its using method
EP1632962A1 (en) * 2004-09-07 2006-03-08 C.R.F. Società Consortile per Azioni Ferromagnetic particles for magnetorheological or electrorheological fluids, magnetorheological or electrorheological fluid including these particles, and manufacturing methods
JP5360126B2 (en) * 2011-04-27 2013-12-04 セイコーエプソン株式会社 Magnetic fluid and damper

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